trinityamps.com

Hi,

Just curious. Is it just me or the documentation is incorrect on these issues.

1- On the schematic pin 8 of the 12ax7 go to R7 a 2k7 resistor.
On the layout pin 8 of the 12ax7 go directly to ground (or wrong side of the R7)

2- On the schematic one side of R18 22k go to the 8 ohms tap of the OT
On the layout it goes to the wiper side of the impedance switch.

And secondly I don't want to be incorrect (sorry my english is not very good) but don't you think that kind of schematic is more user friendly since we don't have every line drawed.

For me it seem much simpler to understand that way. +Voltage is on top, ground is on the bottom. etc.

Hope that a schematic from another site is not a bad idea. I post it just to validate my point.

Thank you for your help

The schem and layout are probably far from finalized. Might want to wait it out for another revision.

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http://pdfelectronics.com

Final versions will be posted shortly.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

oh! sorry then,

I was under the impression, since the first production unit have been builded, that the schematic and the layout doc were finalized. My fault.

For the second point, I am still puzzled. It seem that I am the only one who find the ax84 schematics simpler to understand. Understand is a big word, follow is surely more appropriate in my case.

Thank's

They are easier to read, but they assume the reader knows electronics i.e. where the +285 VDC comes from. I prefer not to leave any questions and to show all the connections. Then it's clear.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

New docs posted.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thank you for the reply Stephen.

I understand your point.

I think theres a mistake on the av84 schematic too! A lot of 18watters tie the filament winding center tap to the top end of the o/p tube cathode resistor to raise the filament voltage above ground by 30 volts or so...but in the schematic shown he's got one side of the filament connected their and not a center tap or a virtual center tap!
Or maybe raising only one side works

It turns out that when you bias or "elevate" the heater supply, connecting one end of the PT's heater winding to the bias voltage is just as effective as connecting the centre tap. If you're just grounding the heater suppl;y, then you need to use the centre tap, or a virtual centre tap formed of a pair of resistors. It also turns out that connecting to a negative bias voltage can be at least as effective, as connecting to a positive.

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